The only con I see, and the biggest one at least for me, is dealing with two property management companies. 

While this is good, the downside is the area may be in decline and recently had a group-home start next door.

And the cash flow is solid when I ran the numbers, but the downside could cap 2020 growth.

The biggest obstacle is creating templates. 

Building your team, lenders, title companies, Realtors, insurance people is the biggest deal in this business, I believe, and a close second for BRRRR is knowing your numbers better than all of them to keep them honest.Max ltv on a refinance is 75% for the most part. 

As for prevention, the biggest thing is to avoid any wood touching the ground.

Hard to see the downside to this if the numbers work with the current income, assuming it's consistent and not depending on the same families coming year in and out due to the relationship with the host.

The biggest lesson that I learned was learning the lingo and what step there are to take, the components of the deal.

The first and biggest problem is that all lenders that I know of will only lend on a transaction that is arm's length, meaning not being purchased from a family member.

My biggest struggle is that I am OCD about timelines and communication....dealing with lenders, escrow officers, other brokers and sometimes clients that ignore timelines and communications brings me a lot of daily frustration.